Eva María Sánchez-Morla

A five-year follow-up study of neurocognitive functioning in bipolar disorder.

Cognitive dysfunction in bipolar disorder has been well‐established in cross‐sectional studies; however, there are few data regarding the longitudinal course of cognitive performance in bipolar disorder. The aim of this study was to examine the course of cognitive function in a sample of euthymic patients with bipolar disorder during a five‐year follow‐up period.

Neuropsychological correlates of P50 sensory gating in patients with schizophrenia

Impaired inhibition of P50 cerebral evoked response is one of the best validated endophenotypes in schizophrenia. There are controversial data on the relationship between P50 evoked potential deficit and measures of cognitive function in schizophrenia. A comprehensive clinical and neurocognitive assessment plus an evaluation of P50 sensory gating was performed in 160 schizophrenia patients and 64 controls. Neurocognitive scores from each cognitive domain were converted to demographically-adjusted T-scores (age, gender, and years of education) for all study participants. The relationship between P50 and neurocognitive variables was assessed via parametric and nonparametric correlations and categorical strategies: we compared neuropsychological test scores in patients and controls in the lowest P50 quartile vs. the highest. Controls had better performance than schizophrenia patients in all cognitive domains. Schizophrenia patients had significantly higher P50 ratios than controls, and no significant correlation was found between P50 gating measures and neuropsychological test scores in schizophrenia patients or healthy controls. Moreover, no differences in neurocognitive performance were found between subjects in the lowest P50 ratio quartile vs. the highest in healthy controls or patients with schizophrenia. We concluded that there is no evidence of an association between P50 ratio and cognitive measures in schizophrenia patients, and this seems to be also the case in healthy controls.

Negative Symptoms and Executive Function in Schizophrenia: Does Their Relationship Change with Illness Duration?

Background: Negative symptoms and cognitive dysfunction are of crucial functional and prognostic importance in schizophrenia. However, the nature of the relationship between them and the factors that may influence it have not been well established. Aims: To investigate whether the relationship between negative symptoms and executive function changes according to the duration of illness in schizophrenia. Methods: The Positive and Negative Syndrome Scale was used to assess psychopathology and the Wisconsin Card Sorting Test (WCST) to evaluate executive function in a sample of 200 schizophrenic patients who were classified in 3 groups according to their duration of illness: up to 5 years (short duration group), 6-20 years (intermediate duration group) and over 20 years of illness (long duration group). Results: Medium-sized correlations were found between negative symptoms and WCST performance as assessed by the number of completed categories in all 3 groups. However, differences were found according to the duration of schizophrenia. For patients in the short duration group, negative symptoms correlated with WCST nonperseverative errors, but for those in the long duration group the correlation was with perseverative errors. Conclusion: We found a differential relationship between negative and cognitive symptoms in different stages of schizophrenia. Illness duration should be considered when studying the relationship between negative symptoms and cognition.

Executive function in schizophrenia: Influence of substance use disorder history

Cognitive function in schizophrenia has been associated with different sociodemographic and clinical variables. Substance use disorder (SUD) history has also been associated with cognition in schizophrenia; however, contradictory results have been found regarding its influence on cognitive function. Our aim was to study the relationship between executive function and a) age, b) duration of illness, c) number of psychotic episodes, d) positive symptoms, and e) negative symptoms, in a sample of schizophrenic patients, and secondly to study whether these relationships persisted after stratification of the sample according to the presence or absence of SUD history. A final sample of 203 schizophrenic patients were evaluated for psychotic symptoms using the PANSS, and assessed using a neuropsychological battery to calculate a composite executive function score. Linear regression analyses were performed, with this executive score as the dependent variable, and age, duration of illness, number of psychotic episodes, positive PANSS score and negative PANSS score as independent variables. For the total sample, the regression model showed three variables to be significant predictors of the executive score: age (p=0.004), number of episodes (p=0.027), and PANSS negative score (p=0.003). However, once the sample was stratified, the regression model showed age (p=0.011) and number of episodes (p=0.011) to be predictor variables for the executive score in the group of schizophrenic patients with SUD history, while age (p=0.028) and PANSS negative score (p=0.006) were predictors in the group of schizophrenic patients without such history. These findings highlight the importance of considering SUD history in studies of cognitive function in schizophrenia.

Emotion processing and psychosocial functioning in euthymic bipolar disorder

To examine emotion processing in euthymic bipolar patients (EBP) compared to healthy controls. In addition, to determine whether or not there is an association between emotion processing and psychosocial functioning.

Prepulse inhibition in euthymic bipolar disorder patients in comparison with control subjects.

Deficient prepulse inhibition (PPI) of the startle response, indicating sensorimotor gating deficits, has been reported in schizophrenia and other neuropsychiatric disorders. This study aimed to assess sensorimotor gating deficits in patients with euthymic bipolar. Furthermore, we analysed the relationships between PPI and clinical and cognitive measures.

Differential Relationships between Set-Shifting Abilities and Dimensions of Insight in Schizophrenia

Background: To assess insight in a large sample of patients with schizophrenia and to study its relationship with set shifting as an executive function. Methods: The insight of a sample of 161 clinically stable, community-dwelling patients with schizophrenia was evaluated by means of the Scale to Assess Unawareness of Mental Disorder (SUMD). Set shifting was measured using the Trail-Making Test time required to complete part B minus the time required to complete part A (TMT B-A). Linear regression analyses were performed to investigate the relationships of TMT B-A with different dimensions of general insight. Results: Regression analyses revealed a significant association between TMT B-A and two of the SUMD general components: ‘awareness of mental disorder and ‘awareness of the efficacy of treatment. The ‘awareness of social consequences component was not significantly associated with set shifting. Conclusions: Our results show a significant relation between set shifting and insight, but not in the same manner for the different components of the SUMD general score.